Was trying to figure out the root cause of some of the facial and bodily proportion distortion in this picture and so I looked at the EXIF data. Considering the Canon IXUS 117 HS has a minimum focal length of 28 mm and the sensor size is 6.2 by 4.6mm, why is it reporting 5mm and 1mm respectively? O_o

That is because of the 1/2.3'' sensor crop factor (5.62x approx.). Just multiply the given focal lenght by 5.62 to get the real focal lenght (28mm approx.). I think we can apply the same for the sensor size.

I asked around and found someone with a IXUS 117 HS. They emailed me some pics. Focal length reports as 28mm and sensor also reports accurately. Also, looking at the four digital cameras I own - ranging from point 'n shoots to bridge cameras to dSLRs - as well as those of my friends, classmates, and the members of the local photography club... I'm not turning up another camera that exhibits that sort of behavior. My two dSLRs are both Canon and I know they don't.